Differential gearing-actuated work holder clamp



Aug. 21, 1962 H. PALAZZOLO 3,050,301

DIFFERENTIAL GEARING-ACTUATED WORK HOLDER CLAMP Filed Sept. 21, 1959 2Sheets-Sheet 1 Tim MENTOR. HENRY PALAZZOLO paw-W ATTORNEYS Aug. 21, 1962H. PALAZZOLO DIFFERENTIAL GEARING-ACTUATED WORK HOLDER CLAMP Filed Sept.21, 1959 2 Sheets-Sheet 2 INVENTOR. HENRY PALAZ ZOLO ATTORNEYS UnitedStates Patent Ofifice 3,56,31 Patented Aug. 21, 1962 3,059,301DIFFERENTIAL GEARING-ACTUATED WORK HOLDER CLAMP Henry Palazzolo, 1393Fontaine Ave., Madison Heights, Mich. Filed Sept. 21, 1959, Ser. No.841,320 6 Claims. (Cl. 269-418) This invention relates generally to thework holder art and more particularly to a novel and improved workholder which incorporates a differential gearing arrangement adapted toactuate a pair of work engaging jaws toward and away from each other soas to clamp a workpiece therebetween.

It is animportant object of the present invention to provide a workholder which may be used as a separate unit or which may be used in setsor groups and operated by suitable interconnecting driving means.

It is another object of the present invention to provide a work holderhaving a pair of jaws which are movable by a differential gearingarrangement and wherein the jaws are each provided with a floating workengaging-body.

It is still another object of the present invention to provide a workholder which is compact and rugged in construction, economical ofmanufacture and efficient in use and operation.

Other objects, features and advantages of this invention will beapparent from the following detailed description and appended claims,reference being had to the accompanying drawing forming a part of thespecification wherein like reference numerals designate correspondingparts of the several views.

In the drawings:

. FIG. 1 is a central, longitudinal, elevational, sectional view of awork holder made in accordance with the principles of the invention,taken along the line 11 of FIG. 2 and looking in the direction of thearrows;

FIG. 2 is an elevational, cross-sectional view of the structureillustrated in FIG. 1 taken along the line 2--2 thereof and looking inthe direction of the arrows;

FIG. 3 is a bottom plan view of the structure illustrated in FIG. 1,taken along the line 3-3 thereof and looking in the direction of thearrows;

FIG. 4 is an elevational sectional view of the structure. illustrated inFIG. 5 taken Substantially along the line 44 thereof and showing aninterconnecting driving structure for operating a plurality of the workholders; and,

FIG. 5 is a broken, longitudinal, elevational, sectional view of thestructure illustrated in FIG. 4 taken along the line 55 thereof andlooking in the direction of the arrows.

Referring now to the drawings, in particular to FIGS. 1, 2 and 3,wherein is shown an illustrative embodiment of the invention, thenumeral indicates a tubular body or housing which is open at the endsthereof and which is substantially circular in cross section. Thehousing 19 is open along one side thereof as indicated in FIGS. 2 and 3by the numerals 1-1 and 12. The housing 10 is provided with the fiatsurfaces '13 and 14 adjacent the opening edges 11 and 12 respectively,as shown in FIG. 2. The open ends of the housing 10 are enclosed by theend plate retainer caps 15 and 16 which are releasably secured to thehousing by any suitable means as by means of the Allen screws 17 and 18,respectively.

As shown in FIG. 1, the work holder is provided with a longitudinallyextended shaft which extends into the housing 10 through the opening 19formed through the retainer cap 16. The inner end of the shaft 20 isrotatably journalled in the bearing 21 which may be of any suitable typeand which is operatively mounted in the recess 22 which is formed in theinner surface of the retainer cap 15. The outer end of the shaft 20extends outwardly of the retainer cap 16 for operative engagement withany suitable tool for turning the shaft, as more fully explainedhereinafter. The shaft 20 is further journalled on the right sidethereof as viewed in FIG. 1, by means of the bearing 23 which may be ofany suitable type, and which is operatively mounted in the recess 24which is formed on the inner side of the retainer cap 16.

Centrally disposed on the shaft 20 and fixedly mounted thereon by meansof the Woodruff key 25 is a diiferential driver means generallyindicated by the numeral 26. The differential driver :means 26 includesthe hub portion 27 which is provided with the pair of integral outwardlyextended stub shafts 23 and 29. Rotatably mounted on the stub shafts 28and 29 are the bevel gears 30 and 32, respectively. The gear 30 isrotatably mounted on the stub shaft 28 by means of any suitable type ofbearing 31 and the gear 32 is similarly mounted by means of the bearing33 on the stub shaft 29. The driving bevel gears 30 and 32 are meshablyand drivingly engaged with the pair of oppositely disposed driven bevelgears 34 and 35 which are integral with and carried by the sleeve shafts36 and 37, respectively. The sleeve shafts 36 and 37 are rotatablyjournalled on the shaft 20 by means of any suitable bearing means as bythe sleeve bearings 39.

A first externally threaded sleeve 40 is fixedly connected by anysuitable means to the sleeve shaft 36 whereby the externally threadedsleeve 40 will be rotated when the bevel gear 34 is rotated, and theexternally threaded sleeve 41 is fixedly connected to the sleeve shaft37 whereby the externally threaded sleeve 41 will be rotated when thebevel gear 35 is rotated. The externally threaded sleeve 40 is providedwith a right hand thread on the periphery thereof and the externallythreaded sleeve 41 is provided with a left hand thread on the peripherythereof. As shown in FIG. 1, the inner ends of the externally threadedsleeves 40 and 41 are adapted to abut against the back sides of thebevel gears 34 and 35, respectively. The externally threaded sleeves 40and 41 are retained in place against the aforementioned gears, toprevent shifting relative to the housing 10, by any suitable bearingmeans as by means of the roller bearing means 42 and 43, respectively.

and 49 are releasably secured to the housing 10 by means of the screws50. It will be seen that the retainer plates 48 and 49 function tomaintain the nuts 44 and in engagement with the worm gears 40 and 41when the externally threaded sleeves are rotated.

Fixedly secured to the nut 44 is the jaw 51. The jaw V 51 may be fixedlysecured to the nut 44 by any suitable means as by screws as 52. The jaw53 is similarly secured to the nut 45 by means of the screw 54. The

jaws 51 and 53 carry the floating work engaging pads 55 and 56,respectively, and these pads are fixed to pivot ball members 57 and 58which are pivotally mounted in the mating recesses 59 and 60,respectively, in the jaws.

As shown in FIG. 1, the shaft 20 is provided with the flange 92 toprevent the shaft from sliding to the right thereof as viewed in FIG. 1.The flange 92 may be integrally formed on the shaft 20 if desired.

In the use of the work holder of the present invention 7 it will beunderstood that the housing may be mounted in any desired position andon any desired machine tool by any suitable means. It will be understoodthat the work holder may 'be made to any desired size. !With the jaws 51and 5?: moved apart, a workpiece may be positioned between the workengaging pads 55 and 56 and the shaft is then turned clockwise, asviewed from the right side of the structure shown in FIG. 1. The shaft20 rotates the bevel gears 30 and 32 clockwise and these gears lock withthe bevel gears 34 and 35 and carry them along in the clockwisedirection as long as the pads 55 and 56 do not engage the workpiece. Assoon as one or the other of the pads engages the workpiece it stops andthe respective bevel gear 34 or 35 will be stationary, as for example,gear 35. The bevel gears 30 and 32 will then continue to drive the bevelgear 34 by differential action whereby the externally threaded sleeve 49will continue to rotate and move the nut 44 inwardly towards theworkpiece. When the pad 55 engages the workpiece the differentialgearing means will serve as a locking means against the pads 55 and 56to prevent them from moving backwards to release the workpiece. In orderto release the workpiece the shaft 20 is merely rotated in the reversedirection. It will be understood that the shaft .20 may be hand or poweroperated.

The work holder of the present invention is adapted for single or pluraluse. That is, it may be used in sets or groups or gangs and be operatedby a driving means as illustrated in FIGS. 4 and 5. FIGS. 4 and 5illustrate the use of a pair of work holders generally indicated by thenumerals 61 and 62. The drive shafts 20a and 20b of the work holders 61and 62 are adapted to be driven by means of the driving means 63. Thedriving means 63 includes a differential gearing arrangement as morefully described hereinafter. The driving means 63 includes the housing64 which is enclosed at the ends thereof by means of the end plates 65and 66 which are secured in place by means of the Allen screws 67. Theend plates 65 and 66 are provided with the hubs 68 and 69, respectively,which are adapted to carry the bearing members 70 and 71 for journallingthe ends of the shafts 20a and 20b, respectively.

The housing 64 is provided with the hollow inside 72 which communicatesat one end thereof with the shaft bore 73 in which is rotatably mountedthe screw shaft 74 by means of the bearing members 74a and 74b. Theshaft 74 is retained in the bore 73 by means of the retainer plate 75which is secured to the housing 64 by means of the screw 76. The shaft74 is provided with the worm threads 77 which meshably engage the ringgear 78 which carries the cage or plate 79 which is secured thereto bymeans of the screws 80. The plate 79 carries the two planetary bevelgears 8-1 and 82 which are rotatably mounted on the shafts 83 and 84,respectively, which are fixed to the plate 79. The gears 81 and 82meshably engage the bevel gears 85 and 86 which are fixedly mounted onthe outer ends of the work holder shafts 20a and 20b, respectively. Theplate 79 is rotatably mounted on the shaft 87 which has its endsrotatably mounted in the bearings 88 and 89 which are mounted in therecesses 90 and 91 in the ends of the shafts 20a and 20b, respectively.It will be seen that when the shaft 74 is rotated, the work holdershafts 20a and 20b will be rotated in accordance with the direction ofrotation of shaft 74. The differential gearing arrangement of thedriving means 63 permits the driving of one of the shafts 20a or 2% whenthe other has stopped due to the fact that the work pads of therespective work holder have made contact with the workpiece. The othershaft will continue to drive until the work pads of the respective workholder have made contact, then they will both drive with equal pressureuntil the workpiece is securely clamped.

While it will be apparent that the preferred embodiments of theinvention herein disclosed are well calcu- 4 lated to fulfill theobjects above stated, it will be appreciated that the invention issusceptible to modification, variation and change without departing fromthe proper scope or fair meaning of the subjoined claims.

What I claim is:

1. A work holder of the class described, comprising: a housing; a driveshaft rotatably mounted in said housing and provided with a differentialdriver means; a differential gearing means having a first pair of gearsrotatably connected to said differential driver means on said shaft;said differential gearing means having a second pair of gears driven bysaid first pair of gears; a pair of externally threaded sleeves fixedlyconnected to said second pair of gears in said differential gearingmeansfor rotation therewith; a pair of work engaging members slidably mountedon said housing for clamping a workpiece therebetween; and, each of saidexternally threaded sleeves being threadably connected to one of saidpair of work engaging members for moving the same.

2. A work holder of the class described, comprising: a housing; a driveshaft rotatably mounted in said housing and provided with a differentialdriver means; a differential gearing means having a first pair of gearsrotatably connected to said differential driver means on said shaft;said differential gearing means having a second pair of gears driven bysaid first pair of gears; a pair of externally threaded sleeves fixedlyconnected to said second pair of gears in said differential gearingmeans for rotation therewith; a pair of work engaging member's slidablymounted on said housing for clamping a workpiece therebetween; each ofsaid externally threaded sleeves being threadably connected to one ofsaid pair of work engaging members for moving the same; and, each ofsaid work engaging members being provided with a pivotally mounted workengaging pad.

3. A work holder means of the class described, comprising: a housing; adifferential gearing means mounted in said housing; a drive shaftmounted in said housing and connected to said differential gearing meansfor driving the same; a plurality of driven shafts connected to saiddifferential gearing means; each of said driven shafts being rotatablymounted in a housing of a work holder and provided with a differentialdriver means; a differential gearing means in each housing provided witha first pair of gears rotatably connected to each of said respectivedifferential driver means on said driven shafts; each of saiddifferential gearing means having a second pair of gears driven by saidfirst pair of gears; a pair of work engaging members being slidablymounted on each of the work holder housings; and, a pair of externallytlneaded sleeves fixedly connected to said second pair of gears forrotation therewith in each of the work holder housings and threadablyconnected with the work engaging members mounted on each work holderhousing.

4. A work holder of the class described, comprising: a housing having alongitudinally disposed opening along one side thereof; a pair of workengaging members slidably mounted on said housing on the outer sidethereof for movement along said opening toward and away from each otherfor clamping a workpiece therebetween; each of said work engagingmembers being provided with a threaded end extended into said housingthrough said opening; a longitudinally disposed drive shaft rotatablymounted in said housing and having one end thereof extended outwardly ofsaid housing; a differential gearing means in said housing having a pairof driving bevel gears and a pair of driven bevel gears meshing withsaid pair of driving bevel gears and driven thereby; said drive shaftbeing drivingly connected to said pair of driving bevel gears; anexternally threaded sleeve fixedly connected to each of said drivenbevel gears; and, the threaded end of each of said work engaging membersmeshing with and being driven by one of said externally threaded sleevesfor moving the work engaging members toward and away from each other forclamping engagement with a workpiece.

5. A work holder as defined in claim 4, wherein: each of said workengaging members is provided with a work engaging pad which is carriedon a pivot ball member pivotally mounted in a mating recess in each jaw.

6. A work holder of the class described, comprising: a first housing; afirst differential gearing means mounted in said first housing; aprimary drive shaft mounted in said first housing and being drivinglyconnected to said first differential gearing means for driving the same;a plurality of secondary drive shafts connected to said firstdifferential gearing means for driving the same; each of said secondarydrive shafts being rotatably mounted in a separate second housing havinga longitudinally disposed opening along one side thereof; a pair of workengaging members slidably mounted on each of said second housings on theouter side thereof for movement along said opening toward and away fromeach other for clamping a workpiece therebetween; each of said workengaging members being provided with a threaded end extended into theirrespective housing through said opening; a second diiferential gearingmeans in each of said second housings having a pair of driving bevelgears and a pair of driven bevel gears meshing with said pair of drivingbevel gears and driven thereby; each of said secondary drive shaftsbeing drivingly connected to a respective pair of driving bevel gears;an externally threaded sleeve fixedly connected to each of said drivenbevel gears; and, the threaded end of each of said work engaging membersmeshing with and being driven by one of said externally threaded sleevesfor moving the work engaging members on each second housing toward andaway from each other for clamping engagement with a workpiece.

References Cited in the file of this patent UNITED STATES PATENTS571,187 Burton Nov. '10, 1896 663,343 Harris Dec. 4, 1900 1,616,627 HuntFeb. 8, 1927 1,811,299 Brockhaus June 23, 1931 1,966,338 Eggimann July10, 1934 2,401,193 Sabin May 28, 1946 2,437,399 Morgan Mar. 9, 19482,511,741 Schulz June 13, 1950

